Honestly a poor swimming destination for small children and a very good pool-and-mud one: the sea itself punishes any splash in the eyes.
The salt is the whole problem
One splash in the eyes ends the afternoon, and nobody should swim face-down or duck under. Under-eights usually get more out of the resort pools than the sea, with a short supervised float as the novelty.
Dead Sea Museum at the Panorama
Open 9am to 5pm, four short sections on how the lake formed, what lives around it and why it is shrinking. Small, air-conditioned, and it takes about half an hour, which is the right length.
The Dead Sea Corniche
The tourist board's promenade along the shore, with cycling tracks, green space and family recreation areas — the one stretch here you can walk along without paying to go through a gate.
Madaba's mosaics in one short visit
St George's church holds the 6th-century mosaic map, and the Archaeological Park nearby is 3 JD. Both are compact and mostly under cover, which makes them the better ruins for children than a long open site.
Mount Nebo
Three dinars, twenty minutes from Madaba, and short enough that nobody complains: a hilltop church with the view down over the Jordan Valley and the Dead Sea that the whole Moses story hangs on.